31 citations · 156 across the 28 of their papers we have counts for
30 papers
Primordial Black Hole Abundances and Scalar Induced Gravitational Waves from Finite-Width Power Spectra in a Stiff Thermal History
Abolhassan Mohammadi, Yogesh, Cristian Joana +2
We study the formation of primordial black holes (PBHs) from large primordial perturbations that re-enter the horizon during an epoch with equation of state . We co…
Evidence for Solar-Cycle Modulation of the Alpha-to-Proton Temperature Ratio in Solar Wind
Aakash Gupta, Yogesh, Dibyendu Chakrabarty +2
The influence of collisional age on the alpha-to-proton temperature ratio has been explored in the past. However, the modulation of this ratio with respect to t…
Statistical insights on the decorrelation lengths of solar wind parameters at L1 point under varying conditions
Yogesh, Aparupa Apsara Baruah, Dibyendu Chakrabarty +3
Understanding the spatial coherence of solar wind plasma and magnetic field properties is essential for interpreting multi-spacecraft observations and for characterizing the large-…
A Starobinsky-like Potential in k-Essence Framework: Attractor Dynamics, Reheating, and Consistency with ACT DR6
Abolhassan Mohammadi, Yogesh, Hongwei Tan +1
The recent ACT DR6 has shifted the preferred value of the scalar spectral index upward so that many well-established inflationary models have been disfavoured, including the Starob…
Finding Novel Precursors for Solar Wind Stream Interaction Regions with Interpretable Deep Learning
Prateek Mayank, Yogesh, Enrico Camporeale +4
Solar wind stream interaction regions (SIRs) drive recurrent geomagnetic storms, yet most existing catalogs rely on expert inspection and simple thresholds that are subjective and…
Constraining Quintessential Inflation with ACT: A Gauss-Bonnet Gateway
Yogesh, Imtiyaz Ahmad Bhat, Mayukh R. Gangopadhyay +1
Recent results from the Atacama Cosmology Telescope (ACT), indicating a higher and more tightly constrained scalar spectral index, , place several inflatio…
Solar Wind Heating Near the Sun: A Radial Evolution Approach
Yogesh, Leon Ofman, Kristopher Klein +19
Characterizing the plasma state in the near-Sun environment is essential to constrain the mechanisms that heat and accelerate the solar wind. In this study, we use Parker Solar Pro…
Observation of Large-Scale Kelvin-Helmholtz Instability Wave Driven by a Coronal Mass Ejection
Leon Ofman, Olga Khabarova, Ryun-Yong Kwon +3
The Kelvin-Helmholtz instability (KHI) can occur when there is a relative motion between two adjacent fluids. In the case of magnetized plasma, the shear velocity must exceed the l…
Spinning Primordial Black Holes and Scalar Induced Gravitational Waves from Single Field Inflation
Abolhassan Mohammadi, Yogesh, Qiang Wu +1
We investigate the formation of primordial black holes (PBHs), their spin and abundance, in a single-field inflationary model based on a mutated hilltop potential inserted with a s…
How the Oblique Drift Instability Alters Solar Wind Heating and Constrains the Distribution of Solar Wind Observations
Mihailo M. Martinovic, Kristopher G. Klein, Leon Ofman +6
Ion-driven plasma instability thresholds, derived from linear theory, constrain the distribution of solar observations in parameter space, defining boundaries of stable plasma para…
Magnetic interaction analysis of multiple interplanetary coronal mass ejections leading to a historic geomagnetic storm in May 2024
Sanchita Pal, Cecilia Mac Cormack, Emilia K. J. Kilpua +3
Interplanetary coronal mass ejections (ICMEs), the large-scale eruptive phenomena capable of shedding a huge amount of solar magnetic helicity and energy are potential in driving s…
Power Law Plateau Inflation and Primary Gravitational Waves in the light of ACT
Abolhassan Mohammadi, Yogesh, Anzhong Wang
We investigate Power-Law Plateau (PLP) inflation in standard gravity and its consistency with ACT DR6 data. While many inflationary models, including the Starobinsky inflation, are…
Identification of Ion-Kinetic Instabilities in Hybrid-PIC Simulations of Solar Wind Plasma with Machine Learning
Viacheslav M Sadykov, Leon Ofman, Scott A Boardsen +5
Analysis of ion-kinetic instabilities in solar wind plasmas is crucial for understanding energetics and dynamics throughout the heliosphere, as evident from spacecraft observations…
Inflationary Dynamics of Mutated Hilltop Inflation in Einstein-Gauss-Bonnet Gravity Under New Slow-Roll Approximations with Generalised Reheating
Yogesh, Mehnaz Zahoor, Kashif Ali Wani +1
The advancement in the observational cosmology of the early universe such as Cosmic Microwave Background (CMB) observations, puts severe constraints on the inflationary models. Man…
Starobinsky like inflation and EGB Gravity in the light of ACT
Yogesh, Abolhassan Mohammadi, Qiang Wu +1
The ACT data shows an enhancement in the value of the scalar spectral index, as , leading to disfavoring many inflationary models, including the Starobinsk…
Evidence of Interaction between Ion-Scale Waves and Ion Velocity Distributions in the Solar Wind
Yogesh, Leon Ofman, Scott A Boardsen +9
Recent in situ observations from Parker Solar Probe (PSP) near perihelia reveal ion beams, temperature anisotropies, and kinetic wave activity. These features are likely linked to…
Modeling hot, anisotropic ion beams in the solar wind motivated by the Parker Solar Probe observations near perihelia
Leon Ofman, Yogesh, Scott A Boardsen +5
Recent observations of the solar wind ions by the SPAN-I instruments on board the Parker Solar Probe (PSP) spacecraft at solar perihelia (Encounters) 4 and closer find ample eviden…
Non-Standard Thermal History and Formation of Primordial Black Holes in Einstein-Gauss-Bonnet Gravity
Yogesh, Abolhassan Mohammadi
Inflation provides a suitable environment for the formation of Primordial Black Holes(PBHs). In this article, we examine the formation of primordial black holes in the Mutated Hill…
Origins of Very Low Helium Abundance Streams Detected in the Solar Wind Plasma
Yogesh, N. Gopalswamy, D. Chakrabarty +4
The abundance of helium () in the solar wind exhibits variations typically in the range from 2-5% with respect to solar cycle activity and solar wind velocity. However, the…
Inflationary Dynamics in Einstein-Gauss-Bonnet Gravity Using New Slow-Roll Approximations considering Generalised Reheating
Yogesh, Imtiyaz Ahmad Bhat, Mayukh R. Gangopadhyay
The Cosmic Microwave Background (CMB) observations results reported by {\it Planck} satellite suggest a plateau characteristic in the flat potential of the inflaton field is favore…
The Dynamics of Reheating in Loop Quantum Cosmology
Yogesh, Bao-Fei Li, Mayukh R. Gangopadhyay +1
In loop quantum cosmology (LQC), the initial singularity is replaced by a quantum bounce, leading to a universal post-bounce evolution characterized by three distinct epochs: bounc…
Understanding the variability of helium abundance in the solar corona using three-fluid modeling and UV observations
Leon Ofman, Yogesh, Silvio Giordano
The variability of helium abundance in the solar corona and the solar wind is an important signature of solar activity, solar cycle, solar wind sources, as well as coronal heating…
Is the NANOGrav detection evidence of resonant particle creation during inflation?
M. R. Gangopadhyay, V. V. Godithi, K. Ichiki +5
We show that the recently reported cosmic gravitational wave background by the NANOGrav 15-year collaboration may be the result of resonant particle creation during inflation. For…
New insights on the behaviour of solar wind protons and alphas in the Stream Interaction Region in solar cycle 23 and 24
Yogesh, D. Chakrabarty, Nandita Srivastava
Although the enhancements in the alpha-proton ratio in the solar wind (expressed as ) in the Interplanetary Coronal Mass Ejections (ICMEs) have been studied i…